1. Field of the Invention
This invention relates to a method and apparatus for preventing generation of black smoke from a coke oven through a chimney after loading raw material coal.
2. Description of the Prior Art
Usually, a coke oven includes a plurality of juxtaposed and alternately disposed combustion chambers and carburization (i.e. meaning introducing carbon into a solid ferrous alloy by heating) chambers so that the latter chambers are heated by the heat generated in adjacent combustion chambers and transmitted through walls partitioning adjacent combustion and carbonization chambers. The exhaust gases from respective combustion chambers are exhausted from the chimney via sole flue exit ports, hot exhaust valves of respective combustion chambers and a common smoke duct.
In a coke oven provided with a heat storage chamber, the hot exhaust valves are switched at a predetermined interval. Odd numbered hot waste valves and even numbered hot waste valves are alternately switched by a longitudinally reciprocating steel operating strip or bar horizontally disposed above the hot exhaust valves.
When cracks are formed through the partition walls after use of long time smoke would efflue from the chimney. More particularly, during an interval of about 15-20 minutes subsequent to the charging of the raw material coal, a large quantity of gas evolves and the gas leaks into the combustion chambers from the carbonization chambers thus resulting in incomplete combustion which forms smokes. Since such smoke causes a public hazard and impairs environmental sanitation it is desirable to reduce as far as possible generation of such smoke.
As a method of preventing the generation of black smoke it is usual to install an electric precipitator in the common smoke duct leading to the chimney. According to this method, however, the whole quantity of the exhaust gas generated by the entire coke oven installation is treated so that a large precipitator is necessary because the quantity of the exhaust gas is large, 1000 to 2000 Nm.sup.3 /min. for example, and because the concentration of the smoke is low which increases the cost of installation and operation.